page_title: Elan Valley Reservoirs
section_title: Dam Busters
hierarchical_section_title: Elan Valley Reservoirs / History / Dam Busters
caption_attribution_description: English: Nant y Gro Dam View of the dam across part of the old spillway. This part is covered in large lumps of debris. I would have thought there would have been more but it must have been swept away in the explosion so could be further downstream or in the lake. http://history.powys.org.uk/history/rhayader/dambuster1.html
context_page_description: The Elan Valley Reservoirs are a chain of man-made lakes created from damming the Elan and Claerwen rivers within the Elan Valley in Mid Wales. The reservoirs, which were built by the Birmingham Corporation Water Department, provide clean drinking water for Birmingham in the West Midlands of England. The five lakes are known as the Claerwen, Craig-goch, Pen-y-garreg, Garreg-ddu, and Caban-coch.
  Water from the reservoirs is carried by gravity to Frankley Reservoir in Birmingham via the Elan aqueduct. Pumping is not required because the network drops 52 metres along its 73 miles length from its source to Frankley. A gradient of 1:2300 maintains a flow of less than 2 miles per hour; water takes two and a half to three days to reach Birmingham. The aqueduct, which was started in 1896 and opened in 1906, crosses several valleys and features numerous brick tunnels, pipelines, and valve houses.
  Work to build the Elan Valley reservoirs was undertaken because the rapid growth of the industrial city of Birmingham in the late 19th century had led to a lack of available clean water.
context_section_description: In 1942, the Nant-y-Gro dam, which had been originally built to provide water for the navvies' village, was used by Barnes Wallis to prove his theory that an underwater explosion could create sufficient hydrostatic pressure to collapse a dam wall. The test proved successful as a significant breach in the middle of the 11-metre (36 ft) dam wall was caused by a charge placed at its base.
  The lessons learned at Nant-y-Gro green lit the development of the "Upkeep" bouncing bombs. They were used in the 1943 Dam Busters raid when RAF Bomber Command breached and damaged several dams in the Ruhr Valley, Germany.
  The remains of the breached Nant-y-Gro dam are in much the same state as it was left in 1942, although partly obscured by trees.
  After the Dam Busters raid, steel cables were strung across the valley above the Caban-coch reservoir as a precautionary measure against German reprisals.
caption: Remains of the breached Nant-y-Gro dam as seen in 2008.
exif: {}